Al2O3: since magnitude of the lattice energy depends on the charge of the cation
and the charge of the anion. The Al ion has the greatest charge, namely +3.
Lattice energy is the energy required to form a lattice from its constituent ions. The smaller the sizes of the ions the higher the lattice energy.
The term lattice energy has to do with the energy that is evolved when a lattice is formed from its constituent ions. We have to note that the lattice energy depends on the respective ion sizes of the ions involved.
The smaller the sizes of the ions the higher the lattice energy and the more likely that the compound will not dissolve in water.
Learn more about ionic lattice: https://brainly.com/question/9496279